Derbyshire Police said a 55-year-old man and a 31-year-old woman from Derby were arrested on Tuesday morning but did not name them.

'Crucial information'Jade Philpott, 10, and brothers John, nine, Jack, seven, Jessie, six, and Jayden, five, all perished in the blaze, while Duwayne Philpott, 13, died of his injuries in Birmingham Children's Hospital two days' later.

In a statement, Assistant Chief Constable Steve Cotterill said: “I suspect there may still be people with crucial information who have not yet come forward to speak to us.

“In view of the arrests, I would urge anyone who may have been holding back, not felt comfortable to voice their concerns or not had the confidence, to do so now. They have my personal reassurance that we will deal with their information sensitively.

“We still need information to help us in this inquiry. The latest arrests are just one step further in the investigation. It is absolutely vital that if you know anything you think could help us, come forward now, do not wait any longer. It is important that we find justice for these six young children.”

A 28-year-old woman and 38-year-old man, both from Derby, were arrested earlier this month on suspicion of murder but were later released without charge, police said.